These screens identified the response regulator PhoP as positive regulators of steA .
phoN promoter promphoNdir promphoNrev FIG 1 PhoP are regulators of steA expression .
In summary , our T-POP-based screens detected PhoP as positive regulators and MgrB as a negative regulator of steA .
These results establish that regulation of steA by PhoQ/PhoP suggest that PhoP could be a direct activator of steA .
These results establish that regulation of steA by PhoQ/PhoP does not occur through activation of the SsrA/SsrB system .
Direct binding of PhoP to the steA promoter .
A slot blot method was used to analyze the binding of PhoP to the promoter of steA .
As seen in Fig. 5 , phosphorylated PhoP was able to bind to the promoter of steA with similar kinetics , whereas no binding was detected to the promoter of phoN .
Finally , slot blot analysis was carried out to test the effect of these mutations in the binding of PhoP to steA promoter .
FIG 5 PhoP binds directly to the promoter of steA .
A direct target of DsbA is SpiA ( also known as FIG 6 The integrity of a putative PhoP box is essential for binding of regulation of steA expression by PhoP .
A direct target of DsbA is SpiA ( also known as FIG 6 The integrity of a putative PhoP box is essential for binding of regulation of steA expression by PhoP .
A direct target of DsbA is SpiA ( also known as FIG 6 The integrity of a putative PhoP box is essential for binding of PhoP of steA expression by PhoP .
phosphorylated PhoP binds then to the steA promoter to directly activate transcription of this gene